Actually, darkness creatures are very OU, with both vampire and upped devourer being in the high 200ks.
All I'm getting is theoretical arguments by comparing SoFre to other cards. Theory always bows to empirical evidence. If you really want to prove to me that it is OP, please design a deck based on SoFre that is very good. Also, do notify me if that happens, since I've been looking for a good SoFre deck for a long time ![Tongue :P](https://elementscommunity.org/forum/Smileys/solosmileys/tongue.gif)
Empirical evidence is not always indicative of balance due to the decks that currently rule the metagame. The problem is the same with SoW, the card is really powerful, but this is counterbalanced with one of the targets being UP (I dare you say that immortals are balanced, I dare you) and this does not mean that the card is balanced. This limits design and forces combos. For example: if Pharaohs had 10 ability cost for 6-attack scarabs (and let's just say 7 upped), would it be UP or OP? With SoR interaction, is it balanced? No. Is this a good idea? No. Does it limit the power of the cards in question if it is to be balanced? Yes. Is it good to improve an UP card using an OP card? Hell no.
And I think you'll agree that SoFo might be balanced if Immolation, Novas and QP did not allow easy casting of the SoFo. Does this warrant a QP nerf? No. If Potato Magical Atonement made it into the game, should we nerf antlion? Is antlion the problem?
I agree.
A deck with cards A and B. (all the above is about the influence of card B)
If Card A is UP and the well designed deck is weak, Card B might be balanced
If Card A is UP and the well designed deck is balanced, Card B might be OP
If Card A is UP and the well designed deck is strong, Card B is likely OP
If Card A is balanced and the well designed deck is weak, Card B might be weak
If Card A is balanced and the well designed deck is balanced, Card B might be balanced
If Card A is balanced and the well designed deck is strong, Card B might be OP
If Card A is OP and the well designed deck is weak, Card B is likely UP
If Card A is OP and the well designed deck is balanced, Card B might be UP
If Card A is OP and the well designed deck is strong, Card B might be balanced